Apparatuses and methods for negative pressure wound therapy

ABSTRACT

Disclosed herein are several embodiments of a reduced pressure appliance and methods of using the same in the treatment of wounds. Some embodiments are directed to improved fluidic connectors or suction adapters for connecting to a wound site, for example using softer, kink-free conformable suction adapters. Certain embodiments are directed to connectors used to connect fluid passage tube used in transmitting negative pressure to a fabric channel used in a suction adapter.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/730,040, filed Jun. 3, 2015, which is a continuation of U.S.application Ser. No. 13/381,884, filed Jul. 12, 2013, which is a U.S.National Phase of the PCT International Application No.PCT/US2011/041521 filed on Jun. 22, 2011, designating the United States,which claims priority to U.S. Provisional Application Ser. No.61/426,432, filed Dec. 22, 2010. The disclosure of each of these priorapplications is incorporated by reference in its entirety and should beconsidered a part of this specification.

FIELD OF THE INVENTION

Embodiments of the present invention relate generally to the treatmentof wounds using negative pressure wound therapy, and more specificallyto an improved apparatus and method thereof.

BACKGROUND OF THE INVENTION

The treatment of open or chronic wounds that are too large tospontaneously close or otherwise fail to heal by means of applyingnegative pressure to the site of the wound is well known in the art.Negative pressure wound treatment systems currently known in the artcommonly involve placing a cover that is impermeable to liquids over thewound, using various means to seal the cover to the tissue of thepatient surrounding the wound, and connecting a source of negativepressure (such as a vacuum pump) to the cover in a manner so that anarea of negative pressure is created under the cover in the area of thewound.

SUMMARY OF THE INVENTION

Embodiments of the invention disclosed herein are directed to a reducedpressure appliance and methods of treatment using a reduced pressureappliance, and may be useful in the treatment of wounds using reducedpressure.

Certain embodiments of the invention employ fluidic connectors and/orsuction adapters for connecting a source of negative pressure to adressing positioned over a wound site. These fluidic connectors and/orsuction adapters offer advantages over the prior art. For example andfor illustrative purposes only, some of the embodiments may offer asofter, kink-free fluidic connector for connecting a wound site to asource of negative pressure for treatment. Such a fluidic connectorand/or suction adapter is faster to apply, requiring fewer stepscompared to prior art connectors, and offers greater patient comfort andsafety by being soft and conformable, thereby avoiding pressure ulcersand other complications caused by harder connectors.

Also disclosed herein are embodiments of an apparatus for providingsuction to a wound site comprising a top and bottom layer constructedfrom a liquid-impermeable material with a 3D knitted or 3D fabricmaterial located between these top and bottom layers and forming anelongate channel.

In another embodiment of a suction adapter, this adapter has anapplicator with an upper and lower surface, with the upper surfaceconnected to the distal end of a bridge. The bridge has a proximal endand a distal end, and has an upper fluid passage connected to an airleak and a lower fluid passage in fluid communication with a source ofnegative pressure, with the lower fluid passage comprising a 3D knittedor 3D fabric material.

In some embodiments of the suction adapter, the upper fluid passage maycomprise foam. The bridge portion may further comprise a top layer, abottom layer and an intermediate layer, each of the layers havingproximal ends and distal ends and elongate portions extendingtherebetween, where the upper fluid passage extends between the top andintermediate layers, and the lower fluid passage extends between theintermediate and bottom layers. The distal end of the bridge may alsohave an enlarged shape. The air leak may be disposed at the proximal endof the bridge. The 3D knitted or 3D fabric material may include a topknitted layer, a bottom knitted layer, and a middle area with verticallyextending fibers, and may be approximately 1.5 to 6 mm thick. The 3Dknitted or 3D fabric material may be constructed so as to resistcompression to less than half its original thickness when subjected to aload of 15 psi.

The suction adapter embodiments above may be used in embodiments of anegative pressure wound treatment system comprising a flexible drapeconfigured to be positioned over a wound and sealed to the skinsurrounding the wound, and where the suction adapter is configured to beattached to the drape so as to surround at least one aperture formed inthe drape. A vacuum pump is preferably connected by at least one conduitto the suction adapter.

Methods of treating a wound with negative pressure are also disclosedherein. A method of treating a wound site with negative pressurecomprises applying a flexible drape over a wound site, applying aflexible suction adapter over an opening in the flexible drape, wherethe flexible suction adapter comprises top and bottom layers constructedfrom a liquid-impermeable material, a 3D knitted or 3D fabric materiallocated between the top and bottom layers, an aperture in the bottomlayer in fluid communication with the wound site through the opening andthe 3D knitted or 3D fabric material, and applying negative pressure tothe wound, the negative pressure being transmitted to the wound throughat least one conduit connected between the source of negative pressureand the flexible suction adapter and passing through the 3D knitted or3D fabric material through the aperture in the bottom layer and into theopening in the flexible drape.

In some embodiments, the application of negative pressure to the woundmay cause air to flow into the wound via an air leak disposed on theflexible suction adapter. The flow rate of air, may, in some embodimentsbe at least 0.08 liters/minute when negative pressure is applied to thesuction adapter, and this flow rate may be maintained while a weight isplaced on the suction adapter, for example a 4.75 kg weight. Adhesivemay be placed on the suction adapter when adhering the adapter to thedrape, or the adapter can be supplied pre-attached to a drape.Otherwise, the method above may comprise cutting an opening into thedrape. Wound contact material can also be placed into the wound siteprior to applying the drape. A similar method may transmit negativepressure to the wound through at least one conduit connected between thesource of negative pressure and the flexible suction adapter and thatpasses through the 3D knitted material into the opening in the flexibledrape.

In another embodiment, a negative pressure wound treatment systemcomprises a conduit, a suction adapter and a connector. The conduit isconfigured to deliver negative pressure to the wound from a source ofnegative pressure. The suction adapter is configured to deliver negativepressure to the wound, wherein the suction adapter comprises an elongatefluid channel having a proximal and a distal end and an elongate 3Dknitted or 3D fabric material extending between the proximal and distalends. A connector is configured to securely attach to a proximal portionof the 3D knitted or 3D fabric material, the connector being furtherconfigured to create a fluidic connection between the 3D knittedmaterial in the elongate fluid channel and the conduit. In certainembodiments, the connector is configured to remain attached to the 3Dknitted or 3D fabric material when subjected to a pulling force of lessthan 20 kg.

In some embodiments, the connector comprises two distally extendingprojections, each projection further comprising at least one barblocated thereon, the barbs configured to be pushed into and be retainedwithin a proximal portion of the 3D knitted or 3D fabric material. Theconnector may further comprise two distally extending projections, eachprojection further comprising at least one barb located thereon, thebarbs configured to attach to upper and lower portions of the 3D knittedor 3D fabric material.

In other embodiments, the connector comprises a central distallyextending projection configured to extend into the 3D knitted or 3Dfabric material. The central projection may further comprise at leastone barb.

In another embodiment, the connector comprises at least one openingconfigured to receive a pin or other locking device, and wherein the pinis pushed through at least a portion of the 3D knitted or 3D fabricmaterial.

In another embodiment, the connector comprises a central channel and atleast one lip configured to be pushed into and secured inside a proximalportion of the 3D knitted or 3D fabric material.

In another embodiment, the connector comprises at least one flexibleline and one corresponding cavity configured to receive the at least oneline, the line being configured to loop into a proximal portion of the3D knitted or 3D fabric material. The line may further comprise at leastone barb.

In another embodiment, a connector for connecting a fluid passage tubeto a fabric channel is provided. The connector comprises a hollowcylindrical body comprising a central channel extending between aproximal end and a distal end of the hollow body. A plurality ofprojections extend distally from the hollow body. A plurality of barbsare provided on each of the projections, wherein the barbs are angledproximally, the barbs being configured to engage the fabric channel. Afrustoconical lip at the proximal end of the hollow body is configuredto be press-fit into the fluid passage tube. The connector is configuredto withstand a pulling force of up to 20 kg before disengaging from thefabric channel.

In another embodiment, the connector for connecting a fluid passage tubeto a fabric channel comprises a body having a proximal end and a distalend. At least one member extends distally from the body, the at leastone member configured to extend into the fabric channel. The proximalend of the body is configured to be press-fit with an inner or outersurface of the fluid passage tube.

In some embodiments, the body may be cylindrical and/or hollow. The atleast one member may comprise a plurality of projections, and theprojections may additionally comprise one or more barbs extending in aproximal direction. The member may alternatively comprise at least oneflexible line, and wherein the line comprises a tapered tip configuredto loop through the fabric channel and be received and securelyconnected to a cavity formed in the connector. The proximal end of thebody may comprise a frustoconical lip.

In another embodiment, a fluidic connection is provided, comprising anyof the aforementioned connectors. A fabric channel is engaged with theproximal end of the connector. A tube is engaged with the distal end ofthe connector.

In another embodiment, a method of transporting fluid. The methodcomprises providing an elongate fluid channel comprising a 3D knitted or3D fabric material. A connector is attached to the 3D knitted or 3Dfabric material, wherein a distal end of the connector engages the 3Dknitted or 3D fabric material. A conduit is attached to a proximal endof the connector. Fluid is transported through the 3D knitted or 3Dfabric material, through the connector and through the conduit.

In some embodiments, the transporting of fluid comprises applyingnegative pressure to the conduit, the connector and the 3D knitted or 3Dfabric material. The 3D knitted or 3D fabric material may be placed influid communication with a wound, wherein applying negative pressurecomprises transmitting negative pressure through the conduit, theconnector and the 3D knitted or 3D fabric material to the wound. In oneembodiment, pulling on the connector with a force less than 20 kg doesnot dislodge the connector from the 3D knitted or 3D fabric material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a negative-pressure system that can be used in thetreatment of wounds.

FIG. 2A illustrates an embodiment of a negative pressure wound treatmentsystem comprising a pump, and illustrating a flexible suction adapterbeing applied to a wound.

FIG. 2B illustrates the embodiment of FIG. 2A, with the flexible suctionadapter having been placed over a wound.

FIG. 2C illustrates an isometric view of a flexible suction adapter thatmay be used in a negative pressure wound treatment system.

FIG. 2D illustrates an exploded view of the flexible suction adapter ofFIG. 2C.

FIG. 2E illustrates a close-up view of the proximal end of the flexiblesuction adapter of FIG. 2D.

FIG. 2F illustrates a close-up cutaway view of the proximal end of theflexible suction adapter of FIG. 2C.

FIG. 2G illustrates a top view of the flexible suction adapter of FIG.2C.

FIG. 2H illustrates a side view of the flexible suction adapter of FIG.2C.

FIG. 2I illustrates a bottom view of the flexible suction adapter ofFIG. 2C.

FIG. 2J illustrates an exploded view of an alternative flexible suctionadapter.

FIG. 3A illustrates a top view of a 3D fabric that may be used in anegative pressure wound treatment system.

FIG. 3B illustrates a bottom view of the 3D fabric of FIG. 3A.

FIG. 3C illustrates a side cutaway view of the 3D fabric of FIG. 3A.

FIGS. 4A-B illustrate an embodiment of a connector with two or moreprojections and that may be connected to a suction adapter illustratedin FIG. 2.

FIGS. 4C-D illustrate an embodiment of a connector with adistally-extending barb.

FIG. 4E illustrates an embodiment of a connector with a central rod.

FIG. 4F illustrates an embodiment of a connector with a securing pin.

FIG. 4G illustrates a similar embodiment to FIG. 4F provided with aprojection.

FIG. 4H illustrates an embodiment of a connector provided with hookedbarbs.

FIG. 4I illustrates an embodiment of a connector provided with a barbdisposed around a central channel.

FIGS. 4J-L illustrate an embodiment of a connector comprising one ormore connectors configured to be received into a corresponding cavity.

FIGS. 5A-G illustrate, respectively, front perspective, front, back,left side, right side, top and bottom views of an embodiment of aconnector with two or more projections.

FIG. 5H illustrates a cross-section of the embodiment of FIGS. 5A-5G.

FIG. 5I illustrates a view of the connector of FIGS. 5A-5H beingconnected into a suction adapter as illustrated in FIG. 2A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments disclosed herein relate to wound therapy for ahuman or animal body. Therefore, any reference to a wound herein canrefer to a wound on a human or animal body, and any reference to a bodyherein can refer to a human or animal body. The term “wound” as usedherein, in addition to having its broad ordinary meaning, includes anybody part of a patient that may be treated using reduced pressure.Wounds include, but are not limited to, open wounds, pressure sores,ulcers and burns. Treatment of such wounds can be performed usingnegative pressure wound therapy, wherein a reduced or negative pressurecan be applied to the wound to facilitate and promote healing of thewound. It will also be appreciated that the negative pressure systemsand methods as disclosed herein may be applied to other parts of thebody, and are not necessarily limited to treatment of wounds.

With reference initially to FIG. 1, treatment of a wound with negativepressure in certain embodiments of the application uses a system asillustrated schematically. In one embodiment, a wound 101 may be partlyor completely filled with a wound packing material 102, such as foam,gauze, or any other suitable material. Alternatively, no wound packingmaterial may be utilized. A flexible drape 103 that is at leastpartially fluid impermeable, and preferably liquid impermeable, may thenbe laid over the wound packing material 102 and preferably onto at leastpart of the surrounding healthy skin surrounding a wound. The drape 103may be connected via a conduit 104 such as a flexible tube to a sourceof negative pressure 106 such as a pump. This conduit 104 may, in someembodiments, comprise one or more tubes. Suitable sources for negativepressure include both powered negative pressure sources such as vacuumpumps, and manually powered negative pressure sources such as suctionbulbs. Negative pressure is applied to the wound through the conduit 104and through the wound packing material 102, and wound exudate and othersecretions are drawn away from the wound, through the wound packingmaterial, and into a canister or other collection unit 105. Thecollection unit 105 may be located along the conduit before the negativepressure source, or may be located elsewhere relative to the negativepressure source. In some embodiments, one or more filters 107 may beprovided along the vacuum pathway, for example at the outlet of thepump. This filter 107 may be useful for absorbing odors or may be abacterial filter. Suitable systems for treating wounds in the abovemanner include the RENASYS-F, RENASYS-G, RENASYS EZ and RENASYS GOsystems available from Smith & Nephew.

The application of reduced or negative pressure to a wound in the abovemanner may be used to promote faster healing, increase blood flow,decrease bacterial burden, increase the rate of granulation tissueformation, remove exudate and slough from the wound, alleviateinterstitial edema, stimulate the proliferation of fibroblasts,stimulate the proliferation of endothelial cells, close chronic openwounds, inhibit burn penetration, and enhance flap and graft attachment,among other things. It has also been reported that wounds that haveexhibited positive response to treatment by the application of negativepressure include infected open wounds, decubitus ulcers, dehiscedincisions, partial thickness burns, and various lesions to which flapsor grafts have been attached.

Suitable drapes such as those used in the embodiments described hereinare preferably liquid tight, such that at least partial negativepressure may be maintained at the wound site. The drape may beconstructed from, for example, transparent flexible plastics such aspolyurethane. Other suitable materials include without limitationsynthetic polymeric materials that do not absorb aqueous fluids,including polyolefins, such as polyethylene and polypropylene,polysiloxanes, polyamides, polyesters, and other copolymers and mixturesthereof. The materials used in the drape may be hydrophobic orhydrophilic. Examples of suitable materials include Transeal® availablefrom DeRoyal and OpSite® available from Smith & Nephew. In order to aidpatient comfort and avoid skin maceration, the drapes in certainembodiments are at least partly breathable, such that water vapor isable to pass through without remaining trapped under the dressing.Lastly, although several embodiments illustrated herein illustrate anoperator cutting an aperture into a drape manually, drapes used in theembodiments disclosed here may also be provided with one or more pre-cutapertures.

The wound is optionally filled with a wound packing material.Preferably, this wound packing material is conformable to the wound bed.This material is preferably soft and resiliently flexible. Examples ofsuitable forms of such wound fillers are foams formed of a suitablematerial, e.g. a resilient thermoplastic. Preferred materials for thepresent wound dressing include reticulated polyurethane foams with smallapertures or pores and open-celled foams. Other suitable materials mayinclude gauze. Preferably, such wound packing material will be able tochannel wound exudate and other fluids through itself when negativepressure is applied to the wound. Some wound packing materials mayinclude preformed channels or openings for such purposes.

Typically, the negative pressure wound treatment system is operateduntil a wound has reached a level of healing acceptable to a physician.The treatment system is preferably operated using a negative or reducedpressure ranging from about 40 to 200 mm Hg, though the amount may belower or higher depending on physician preference. The time period foruse of the wound treatment apparatus on a wound is selected by thephysician. During the time period that negative pressure is applied,dressing changes and other temporary interruptions to the treatment mayoccur. Preferably, the negative pressure wound treatment system is ableto handle at least 1 L of wound exudate or other fluid per day, or 0.694ml/min. Some embodiments may handle over 10 L of wound exudate per day.

In preparing a wound site for treatment with the embodiments describedherein, the wound is typically cleaned, debrided, and dried in amedically-acceptable manner. Optionally, the wound site may be filledpartly or completely with a wound packing material 102 as shown in FIG.1, including for example but without limitation gauze or foam. Thiswound packing material may be trimmed to fit into the wound space. Next,a drape 103 is placed to cover the wound site while overlapping onto thehealthy skin surrounding the wound; in some cases, the drape may need tobe trimmed to size. Depending on the type of drape, a skin sealant mayneed to be applied to the skin surrounding the wound prior to placingthe drape so that the drape may be adhered to the skin. Preferably, thedrape 103 has an adhesive layer on its wound-facing side. Once adheredto the skin, the drape should form an air-tight seal against the skin.In order to treat the wound using negative pressure, some embodimentsdisclosed herein may require that the drape be pierced (for example toinsert a conduit or to communicate with a suction adapter as describedbelow) to create an aperture leading to the wound site. Obviously, somedrapes may have an aperture or apertures already pre-cut or preformedinto the drape, and some embodiments disclosed herein may not require anaperture to be made (as shown in FIG. 1). After application of negativepressure to the wound site, wound exudate and other fluids may be drawnaway from the wound site and into a suitable receptacle 105, preferablyinterposed between the wound site and the source of negative pressure106. Application of negative pressure is continued (with interveningdressing changes, if necessary) until the wound has reached a desiredlevel of healing.

FIGS. 2A-J illustrate embodiments of a negative pressure wound treatmentsystem 5501. Here, the system 5501 may comprise a bridge 5502 having aproximal end 5503 and a distal end 5505 and an applicator 5520 at thedistal end 5505 of the bridge 5502 forming a flexible suction adapter.Preferably, the system 5501 comprises a bridge 5502. A connector 5504 ispreferably disposed at the proximal end 5503 of the bridge 5502, so asto connect to at least one of the channels 5512 and/or 5516, as shown inFIG. 2D. A cap 5536 may be provided with the system 5501 (and can insome cases, as illustrated, be attached to the connector 5504). The cap5536 can be useful in preventing fluids from leaking out of the proximalend 5503. In some embodiments, the connector 5504 may be an MQC Series™quick connector, as sold by Value Plastics (Fort Collins, Colo.). Thesystem 5501 may include a source of negative pressure such as a pump ornegative pressure unit 5534 capable of supplying negative pressure. Thepump also preferably comprises a canister or other container for thestorage of wound exudates and other fluids that may be removed from thewound. In some embodiments, this pump 5534 can be a RENASYS GO pump, assold by Smith & Nephew. The pump 5534 may be connected to the connector5504 via a tube 5540. In use, the applicator 5520 is placed over anaperture 5535 formed in a drape 5531 that is placed over asuitably-prepared wound 5530, which may in some cases be filled with awound packing material such as foam or gauze. Subsequently, with thepump 5534 connected via the tube 5540 to the connector 5504, the pump isactivated, thereby supplying negative pressure to the wound. Applicationof negative pressure may be applied until a desired level of healing ofthe wound 5530 is achieved.

Here, and with particular reference to FIGS. 2C-D, the system 5501 maycomprise a bridge 5502 having a proximal end 5503 and a distal end 5505and an applicator 5520 at the distal end 5505 of the bridge 5502. Insome embodiments, the bridge 5502 may comprise an upper channel layer5512 positioned between an upper layer 5510 and an intermediate layer5514, with a lower channel layer 5516 positioned between theintermediate layer 5514 and a bottom layer 5518. Preferably, the layers5510, 5514, and 5518 have elongate portions extending between proximaland distal ends and may be comprised of a material that isfluid-impermeable, for example polymers such as polyurethane. It will ofcourse be appreciated that the layers 5510, 5514, and 5518 may each beconstructed from different materials, including semi-permeablematerials. As illustrated in FIG. 2D, the upper and lower layers 5510and 5518 may be curved, rounded or outwardly convex over a majority oftheir lengths. During assembly, for example, the layers 5510, 5514, and5518 may be pinched together to weld or adhere the layers together. Indoing so, the proximal ends of the channels 5512 and 5516 may besandwiched between these layers, thus partially compressing the proximalends of the channels 5512, 5516 and stretching the layers 5510, 5514,5518 over these aforementioned proximal ends. Of course, the proximalends of the materials used in the bridge section 5502 may notnecessarily be rounded or curved; as shown in FIG. 2J, they can remainsubstantially squared off and straight.

The upper and lower channel layers 5512 and 5516 are preferably elongatelayers extending from the proximal end 5503 to the distal end 5505 andmay each preferably comprise a porous material, including for exampleopen-celled foams such as polyethylene or polyurethane. In someembodiments, one or more of the upper and lower channel layers 5512 and5516 may be comprised of a fabric, for example a knitted or woven spacerfabric (such as a knitted polyester 3D fabric, Baltex 7970®, or Gehring879®) or a nonwoven material. Suitable materials may also includeterry-woven or loop-pile materials. The fibers may not necessarily bewoven, and can include felted and flocked (including materials such asFlotex®) fibrous materials. The materials selected are preferably suitedto channeling wound exudate away from the wound and for transmittingnegative pressure and/or vented air to the wound site, and may alsoconfer a degree of kinking or occlusion resistance to the channel layers5512 and 5516 as described below. In one embodiment, the upper channellayer 5512 may comprise an open-celled foam such as polyurethane, andthe lower channel layer may comprise a fabric as described herein. Inanother embodiment, the upper channel layer is optional, and the systemmay instead be provided with an open upper channel. In the embodimentillustrated in FIG. 2D, the upper channel layer 5512 may have a curved,rounded or upwardly convex upper surface and a substantially flat lowersurface, and the lower channel layer 5516 may have a curved, rounded ordownwardly convex lower surface and a substantially flat upper surface.

In some embodiments, the fabric may have a three-dimensional structure,where one or more types of fibers form a structure where the fibersextend in all three dimensions. Such a fabric may in some cases aid inwicking, transporting fluid, and/or transmitting negative pressure. Toprevent the channels 5512 and/or 5516 from being displaced or twistedwhile encased in the system 5501—which may impair performance of therespective channels under negative pressure—it may in some embodimentsbe preferable to adhere or otherwise secure the channels 5512 and/or5516 to one or more of the layers 5510, 5514, and 5518. In certainembodiments, these materials remain open and capable of communicatingnegative pressure to a wound area under the typical pressures used innegative pressure therapy, for example between 40 to 150 mmHg, althoughhigher and lower values are possible. In some embodiments, the fabricmay comprise several layers of material stacked or layered over eachother, which may in some cases be useful in preventing the channel 5516from collapsing under the application of negative pressure. In otherembodiments, the fabric used in channel 5516 may be between 1.5 mm and 6mm; more preferably, the fabric may be between 3 mm and 6 mm thick, andmay be comprised of either one or several individual layers of fabric.In other embodiments, the channel 5512 may be between 1.2-3 mm thick,and preferably thicker than 1.5 mm. Additionally, and as describedpreviously, the materials used in the system 5501 are preferablyconformable and soft, which may help to avoid pressure ulcers and othercomplications which may result from a wound treatment system beingpressed against the skin of a patient. Further examples of 3D fabricsare discussed below in FIGS. 3A-C.

Preferably, the distal ends of the layers 5510, 5514, and 5518 and thechannel layers 5512 and 5516 are enlarged at their distal ends (to beplaced over a wound site), and may form a “teardrop” or other enlargedshape. The distal ends of at least the layers 5512, 5514, 5516, and 5518may also be provided with at least one through aperture. This aperturemay be useful not only for the drainage of wound exudate and forapplying negative pressure to the wound, but also during manufacturingof the device, as these apertures may be used to align these respectivelayers appropriately.

With additional reference to FIGS. 2D-E and J, a channel connector 5506is provided at the proximal end 5503 of the bridge 5502, the channelconnector 5506 preferably being configured so as to be embedded into thelower channel layer 5516 so as to create a secure fluidic connection.The channel connector 5506 may in some embodiments be inserted into apre-made cavity formed into the channel 5516; as illustrated in FIG. 2J,this cavity can be cut out or can be in the form of a rabbet joint. Insome embodiments, the channel connector 5506 may be one of theconnectors described in FIGS. 4A-L below. With one end of the channelconnector 5506 being embedded into the lower channel layer 5516, theother end of the channel connector 5506 may be connected or incommunication with, in one embodiment, a connector tube 5507, althoughin some embodiments the channel connector 5506 may be connected directlyto the connector 5504, or else connected directly to a tube 5540connected to a source of negative pressure. When using a connector tube5507, the resulting assembly can permit a connector 5504 to be attachedthereto. A cap 5536, which may be secured to the suction adapter forexample via a cap leash 5527 secured with a ring disposed on the outersurface of the connector tube 5507. The cap 5536 may be used to coverthe end of the suction adapter, for example at the connector 5504, so asto prevent exudate and other wound fluids from leaking out. Theconnector 5504 is preferably configured to connect with a tube 5540connected to a source of negative pressure. The connector 5504 may forexample comprise a lip or other such structure to aid in securing theconnector 5504 to a tube 5540 and/or cap 5536, although it will beunderstood that other connector types are possible, includingquick-disconnect couplings, luer locks, Christmas-tree, and other suchconnectors.

The upper layer 5510 may comprise additional material extendingdownward, preferably at least of the thickness of the bridge 5502; thismaterial may then be used to bond or weld to the other layers so to forma fluid-tight seal. More specifically, during assembly, the upper layer5510 may be attached, for example by melting, welding, or withadhesives, to the lower layer 5518 so as to form a fluid-tight seal(with the exception of the apertures at the distal and proximal ends).Preferably, the middle layer 5514 is attached to the top layer 5510 andthe bottom layer 5518. In some embodiments, it may be preferable toattach or bond the connectors 5504 and/or 5506, as well as the tube 5507to at least one of the layers 5510, 5514, 5518 so as to create afluid-tight connection. To provide for a more secure connection, someembodiments may also be provided with a weld 5532 made onto the lowerlayer 5518. The lower channel 5516 may have a hole or aperture madethrough it, which may be used to weld it, via the weld 5532, to thelower layer 5518. This welding of the lower channel 5516 to the lowerlayer 5518 via the weld 5532 made through the hole 5533 may thus aid inpreventing the various layers and channels from shifting or beingdisplaced. Obviously, it will be understood that other securement meansmay be used, for example adhesives and the like, and that sucharrangements may be also be used in the upper channel 5512.

In certain embodiments, for example as illustrated in FIGS. 2C-J, acontrolled air leak 5524 may be disposed on the bridge portion 5502, forexample at the proximal end thereof. This air leak 5524 may comprise anopening or channel extending through upper layer 5510, such that the airleak 5524 is in fluidic communication with the upper channel 5512. Uponthe application of suction to the system 5501, air will enter throughthe air leak 5524 and move from the proximal end 5503 to the distal end5505 along the upper channel 5512. The air will then be suctioned intothe lower channel 5516 by passing through the apertures through thedistal ends of the layers 5512, 5514, 5516 and 5518. The air leak 5524preferably comprises a filter 5525. Preferably, the air leak 5524 islocated at the proximal end of the bridge portion 5502 so as to minimizethe likelihood of wound exudate or other fluids coming into contact andpossibly occluding or interfering with the air leak 5524 or its filter5525. In some embodiments, this filter 5525 is a microporous membranecapable of excluding microorganisms and bacteria, and which may be ableto filter out particles larger than 45 μm. Preferably, the filter 5525can exclude particles larger than 1.0 μm, and more preferably, particleslarger than 0.2 μm. Advantageously, some embodiments may provide for afilter 5525 that is at least partially chemically-resistant, for exampleto water, common household liquids such as shampoos, and othersurfactants. In some embodiments, reapplication of vacuum to the system5501 and/or wiping of the exposed outer portion of the filter 5525 maybe sufficient to clear any foreign substance occluding the filter 5525.The filter 5525 may be composed of a suitably-resistant polymer such asacrylic, polyethersulfone, or polytetrafluoroethylene, and may beoleophobic and/or hydrophobic. In some embodiments, the filter 5525 mayalso comprise a supporting backing layer, for example a nonwovenpolyester support. Preferably, the air leak 5524 will supply arelatively constant air flow that does not appreciably increase asadditional negative pressure is applied to the system 5501. Inembodiments of the system 5501 where the air flow through the air leak5524 increases as additional negative pressure is applied, preferablythis increased air flow will be minimized and not increase in proportionto the negative pressure applied thereto.

The filter 5525 provided in the controlled air leak 5524 in certainembodiments may be useful in a system 5501 for use with more ambulatoryand active patients. For example, a chemically-resistant filter maypermit a patient to bathe or shower without damaging the filter'sfunctionality when reconnected to a source of negative pressure. Anyocclusion or fluid blocking the air leak 5524 could then be cleared by,for example, wiping off the filter 5525 or re-applying negative pressureto the system 5501. Such a system would also have the advantage that thesystem 5501 and any assorted wound dressing materials, if present, wouldnot need to be removed and then re-applied should a patient need to bedisconnected from the source of negative pressure, for exampleincidental to bathing. This would entail significant advantages inimproving the cost-effectiveness and ease of use of the presenttreatment system.

The system 5501 is preferably constructed so as to provide a consistentfluid flow even if the system 5501 is kinked or weighted down. Forexample, in use on a patient, the bridge portion 5502 may become foldedover itself, or else the patient may roll over, thus placing his or herweight over at least a portion of the system 5501. Typically, prior artdressings and fluidic connectors become blocked or ineffective in suchsituations and in some cases may contribute to complications such aspressure ulcers. Here, however, certain embodiments provide for improvedblockage resistance if kinked or weighed down. Preferably, by employingchannel layers 5512 and 5516 as described above, and more preferably byemploying a foam channel layer 5512 and a fabric channel layer 5516, thesystem 5501 is able to maintain a flow rate through the air leak 5524 ofat least 0.08 L/min, and preferably 0.12 L/min while negative pressureis applied through a source of negative pressure. Further embodimentsalso provide for the system 5501 to be able to handle fluid exudatedrainage from the wound site through the lower channel 5516 of at least10 L/day, or 6.9 ml/min. Certain embodiments provide for the system 5501to maintain these flow rates with a weight, for example a 12 kg weight,pressing down on the bridge portion through a rod with a 1 in. diameter.In some embodiments, these flow rates are also maintained while thebridge portion 5502 is kinked over itself with the same weight, or forexample with a 4.75 kg weight placed directly on the folded region. Itis preferable that the system 5501 be able to withstand being folded orkinked over even during an extended period of time, for example over 40hours, and not show any degradation in performance (e.g., flow rates)compared to its performance prior to being folded or kinked over.Preferably, embodiments of the system 5501 are also able to transmit andmaintain a negative pressure at the wound that is close to the negativepressure level at the source of negative pressure. For example, anacceptable level of pressure maintained at the wound may be within ±25mmHg of the negative pressure set at the source of negative pressure,with this pressure being preferably maintained at this level within 95%of the time that the system 5501 has negative pressure applied to it.Acceptable pressure levels may include pressure ranges between 40-120mmHg, although levels of 200 mmHg have successfully been used.

With additional reference to FIGS. 2A-D, G-J, the system 5501 alsocomprises an applicator 5520 designed for placement over a wound site.Preferably, the applicator 5520 comprises a flexible layer 5550, forexample polyethylene or polyurethane, with a layer of adhesive on itslower (wound-facing) side. Optionally, a protective release layer 5529may be placed on the adhesive layer, which is removable before use. Insome embodiments, a more rigid removable backing layer 5552 may beprovided on the upper side of the applicator 5520 to facilitate handlingof the applicator 5520 due to the flexibility of the layer 5550. Theapplicator 5520 preferably comprises an attachment point for the bridge5502 at the distal end 5505, for example using a section of double-sidedadhesive tape 5528. The double-sided adhesive tape 5528 may be protectedby an additional protective release layer, which is removed prior toadhering the bridge 5502 to the applicator 5520. It will be understoodthat different attachment methods are also contemplated, for exampleheat sealing, welding, or suitable adhesives. Some embodiments may alsopermit the manufacture of the bridge 5502 and the applicator 5520 as asingle unit that does not require separate attachment means. Theapplicator 5520 preferably comprises at least one aperture 5526 throughitself and designed to be placed over a wound site, and which can serveto fluidically connect the wound site to the source of negative pressureand to the air leak while also serving as a conduit to draw out woundexudate from the wound site.

In use, and with reference to FIGS. 2A-B, the system 5501 may be used ina similar fashion to the other embodiments previously disclosed herein.A wound site 5530 is preferably cleaned and prepared in a suitablefashion, and a wound packing material, if necessary, placed into thewound site, followed by a drape 5531. An aperture 5535 through the drapeto the wound site is then created, although some embodiments may have apre-made aperture 5535. Subsequently, an operator may situate theapplicator portion 5520 over the aperture 5535. After removing thebacking layer 5529 (if present) from the adhesive layer on the undersideof the applicator portion 5520, the applicator is sealed to the drape5531, and the backing layer 5552 (if present) is also removed from theapplicator portion 5520. A fluidic conduit such as a tube 5540 may thenbe connected to the connector 5504. The tube 5540 may also be connectedto connector 5504 prior to applying the applicator to the wound site.The fluidic conduit is connected to a source of negative pressure 5534,preferably with a container suitable for containing wound exudateinterposed therebetween. The application of negative pressure may thenbe effectuated to the wound site 5530 until the wound site progresses toa desired level of healing.

During use of the system 5501, wound exudate from the wound site 5530 isdrawn by the negative pressure through the lower channel layer 5516. Theair leak 5524 allows air to pass through the upper channel layer 5512into the apertures through the distal ends of the layers 5512, 5514,5516 and 5518. The negative pressure draws air passing through the upperchannel layer into the lower channel layer 5516 back toward the sourceof negative pressure or pump. In some embodiments, the controlled airleak 5524 provides a constant flow of air through the system 5501, whichthen may be used to determine whether blockage or leakage is present.Causes of blockage can include, for example, situations where the lowerchannel 5516 becomes occluded with wound debris. Leakage causes caninclude, for example, improper sealing of the drape over the wound site,or physical damage to the system 5501 leading to excess air leaking intothe system. The blockage or leakage may be determined, in certainembodiments, by measuring the speed of the pump while the pump works tomaintain a constant negative pressure. Pump speed may also be measuredindirectly by measuring the amount of voltage or signal sent to thepump.

FIGS. 3A-C illustrate views of a 3D fabric that may be used in variousembodiments described herein, for example the bridge 5502 of the suctionadapter illustrated in FIGS. 2A-J. Although other porous materials suchas foam may be used in the embodiments described herein, for example inthe upper and lower channels 5512 and/or 5516 illustrated in FIGS. 2A-C,the use of 3D fabrics may be advantageous in some circumstances. Certain3D fabrics have been found to perform well in conveying negativepressure to and wound exudate from a fluidic suction adapter, even whileunder compression—for example when a patient's weight is placed directlyupon the suction adapter, or when negative pressure is applied—and/orwhen the fluidic suction adapter is kinked or folded. Some 3D fabricsthat have been found to perform acceptably include knitted polyester 3Dfabric, Baltex 7970®, Gehring 879®, or Coolmax®. Of course, other fibersand fabric types may be used in part or in whole to make 3D fabrics, andinclude without limitation polyamides such as nylon, viscose, cotton, aswell as other synthetic microfibers. 3D fabrics may also be constructedat least in part from fibers such as Nomex® and Kevlar®. Other types offabrics and materials disclosed elsewhere herein may also be used.

In one embodiment, as illustrated in FIGS. 3A-C, the 3D fabric maycomprise a bottom side 5603, a top side 5605, and an open middle area5607. FIG. 3A illustrates the bottom (wound-facing) side 5603 of a 3Dfabric, which may be woven so as to create oblong or ovoid openings 5611extending lengthwise across the fabric. In one embodiment, the oblong orovoid openings 5611 represent or provide an open area of between 10 and45% (or about 10% to about 45%) of the surface area of the bottom layer,more preferably 10% to 30% (or about 10% to about 30%). Here, fibers areknitted (for example by warp knitting) so as to also include theselarger openings or pores that permit bulk transport of wound fluids inaddition to wound fluids carried along the fibers by capillary action ofthe fibers. Apertures that are optionally formed in the distal end ofthe 3D fabric (as illustrated in FIGS. 2D and J) may also aid in thebulk evacuation of wound debris and fluids.

FIG. 3B illustrates the top side 5605 of a 3D fabric that may be used asdescribed herein. This top side 5605 in one embodiment does not have thelarger ovoid apertures 5611 of the bottom side 5603, but may haveopenings 5613 defined by fibers extending lengthwise and generallytransversely or at an angle across the width of the fabric. Asillustrated, these openings are generally rhombus-shaped. In oneembodiment, these openings 5613 may represent or provide an open areagreater than that of the bottom layer, for example between 30% and 50%(or about 30% and about 50%). Of course, it will be understood that thefabric presented here is a non-limiting example, and different fabricconfigurations and orientations are possible, for example with the topside 5605 being placed downward so as to face the wound and with thebottom side 5603 facing upward.

FIG. 3C illustrates a cross-section of a 3D fabric (the bulb-likeprojections on the vertical fibers in the fabric are an artifact of thecutting process). The vertically extending fibers 5609 may be woven soas to extend through the middle open area 5607 while also beingconnected to the bottom and top layers 5603 and 5605. Preferably, thefibers 5609 present in the open middle layer 5607 will have sufficientstiffness so as to help prevent compression of the fabric. Asillustrated in this figure, and without wishing to be bound by theory,3D fabrics that have been found to perform well will often include alarger open area 5607 in the middle portion that may permit exudates andother fluids to be effectively transported away from a wound site whileunder the application of negative pressure, while more densely-wovenouter layers 5603, 5605 may aid in providing additional tensile strengthand capillary wicking action. For example, the middle layer may includean open volume of greater than 50% (or greater than about 50%).Obviously, the resulting fabric cannot be too thick or composed offibers that are too stiff, as the resulting suction adapter and systemmay not remain sufficiently flexible for comfortable usage with apatient.

It will often be advantageous to tailor the performance characteristicsof the 3D fabric while in use to account for various requirements of thesuction adapter. In particular, the flow rate of exudate through thefabric, for example when under compression, may be simplified byconsidering the porosity of the fabric. In such situations, and againwithout wishing to be bound by theory, the porosity of the fabric, andthus the space that will be available for fluids to travel through, maybe determined in part by the knit pattern of the fibers used in creatingthe 3D fabric, the thickness of the fibers used therein, and theirrespective stiffness and hardness (especially when under compression).Fibers may also be modified by surface properties (the fibers can beflat or textured) and the number of fibers or filaments used in theresulting fabric. Compression resistance may be affected by the choiceof fiber or monofilament used in the vertical axis of the fabric, andgenerally, a stiffer material will improve compression resistance onthis axis. Other materials properties, such as hydrophobicity, may playa role. In some cases, it may be beneficial to treat the fabric to behydrophilic, for example with a hydrophilic polymer, so as to improvewicking of fluids. Preferred embodiments of the 3D fabric used withcertain suction adapters have been found to work well when Baltex®fabric is treated in such a fashion. Other possible treatments mayinclude lipophilic coatings to prevent proteins from adhering andbuilding up during use, which may cause clogging and loss of pressure tothe wound site.

The flow rate through the 3D fabric while under the application ofnegative pressure may be approximated by considering each opening as aseparate orifice plate subject to Bernoulli's principle while underlaminar flow. To simplify calculations, the area of openings for a givenarea of 3D fabric may be used. Thus, the 3D fabric may be optimized toachieve a good balance between factors such as the compressionresistance required and the resulting flow rate under the application ofnegative pressure. Further optimization will also take place with thestiffness and flow rate of the 3D fabric being tailored to applicationin the embodiments described herein. Optimization of the properties anddimensions of the 3D fabric will also preferably take into account abalancing between the flow rate and stiffness required and theconformability of the fabric, as a fabric that is too stiff may not bendappropriately and may also be uncomfortable on the patient. The 3Dfabric should preferably be designed so as to yield when compressedagainst tissue, thereby preventing tissue compression (for exampleagainst bony prominences in the patient) and the discomfort and damage,such as pressure ulcers, that may follow. For example, the dimensions ofthe fabric may be tailored for the ultimate use of the suctionadapter—smaller in the case of distal extremities such as fingers, andlarger for abdominal and burn wounds. A fabric that is too stiff mayalso cause pressure ulcers and other such complications, although it mayfunction acceptably in larger dimensions.

In practice, and as also described previously herein, flow rates throughembodiments of the suction adapter using 3D fabrics are at least 0.08L/min, preferably up to 10 L/min during the application of negativepressure, and should be able to handle fluid exudate drainage of atleast 10 L/day. Some embodiments of the suction adapter may beconfigured to handle much larger wounds, including abdominal wounds, andwhich in some cases may exude at least 0.5 L/hr, or 12 L/day. In moreextreme cases, the pump used (for example, the RENASYS EZ) may be ableto evacuate up to 16 L/min, thereby evacuating a large wound to anegative pressure level of 120 mmHg in less than a minute. The pressuredrop calculated due to the 3D fabric should be minimal, and the level ofnegative pressure measured at a wound site is preferably within 25 mmHgof the pressure level measured at the source of negative pressure.Although the pressure drop increases as the negative pressure appliedincreases (thus rendering the 25 mmHg target more difficult to reach),embodiments of the wound treatment system are preferably able tomaintain this target pressure to at least a negative pressure of 200mmHg. The suction adapter and system are preferably able to functionwithin pressure ranges required for negative pressure, which areestimated to be from around 40 mmHg to 200 mmHg. Pressure ranges greaterthan 200 mmHg are possible, but these may in some circumstances causepatient discomfort. The apparatus may also function at lower pressureranges, such as 20 mmHg, although at such low pressure levels thetherapeutic effects resulting from negative pressure may be diminished,with the device acting more as a drainage device. Preferably,embodiments of a negative pressure treatment system are able to maintainthese target pressures at the wound site within 95% of the time thatnegative pressure is being applied to the wound. In some embodiments,the fabric may comprise several layers of material stacked or layeredover each other, which may in some cases be useful in preventing thechannel 5516 from collapsing under the application of negative pressure.In other embodiments, the fabric used in channel 5516 may be between 1.5mm and 6 mm; more preferably, the fabric may be between 3 mm and 6 mmthick, and may be comprised of either one or several individual layersof fabric. In other embodiments, the channel 5512 may be between 1.2-3mm thick, and preferably thicker than 1.5 mm. Preferably, the 3D fabricis able to withstand a load of at least 5.3 psi with a compression ofnot more than 10% of the fabric's original thickness. Further, the 3Dfabric may also be able to resist compression to less than half of itsoriginal thickness when subjected to a load of 15 psi.

In a preferred embodiment, a 3D fabric may be woven from 100% polyesterusing yarns of 150 and 225 Denier, to yield a fabric weighingapproximately 23 to 25 oz per square yard. In these cases, the fabricmay be approximately 5.8-6.8 mm thick. The bottom portion of the fabricmay also have several openings or pores 5611 similar to thoseillustrated in FIG. 3A, which may be elongated, rectangular or ovoid inshape and oriented with their long axis lengthwise along the fabric. Theopenings 5611 may be arranged in a plurality of rows extendinglengthwise across the fabric, for example 2 to 5 rows, or morepreferably 3 rows as illustrated in FIG. 3A. The openings 5611 may bespaced equidistantly from each other in each of the rows, and may form astaggered pattern from one row to another. In one embodiment, each rowmay have approximately 6-10 openings, more preferably 8 openings, per 2inches (or about 50 mm). Along a given width or transverse dimension ofthe fabric, the transverse rows formed by the openings may have aspacing of approximately 6-10 openings, more preferably 8 openings, per2⅛ inches (or about 54 mm). In one embodiment, the openings may have alength of between about 1/16″ to about 1″ lengthwise, and a width ofbetween about 1/32″ and ½″ widthwise. In one example, the openingsmeasure approximately ⅛″ (or about 3.2 mm) lengthwise and 1/32″ (orabout 0.79 mm) across. The 3D fabric in one embodiment may have anoverall length of between about 50 and 100 mm, more preferably about 60mm, a width between about 5 and 15 mm, more preferably about 9 mm, and athickness of about 6 mm.

Embodiments of the systems described herein have been tested and foundto perform satisfactorily. Such testing was performed by constructingsuction adapters from embodiments described herein. The distal ends ofthe suction adapters were then placed over an aperture made onto a drapeplaced over a simulated wound cavity provided with a source of simulatedwound fluid, which was controllable and which can vary the flow rate ofthe wound fluid. The simulated wound cavity was also in some casespacked with foam or some other wound packing material. In some tests,the simulated wound fluid was a 5:1 water to glycerol mix, and in othersfiltered horse serum (available from Oxoid, United Kingdom) was used.The proximal end of the suction adapter was then connected to a sourceof negative pressure, in this case a pump. Flow rate tests and othermeasurements were then conducted at various negative pressure ranges andsimulated exudate flow rates and air leak rates.

FIGS. 4A-L illustrate embodiments of a connector 5704, similar to theconnectors 1504 and 5506 described previously, and which may be used tosecurely connect a source of negative pressure to a channel 5716 of asuction adapter such as the ones described herein. For example, thischannel 5716 may be the channels 5512 and 5516 in FIGS. 2-3. Generally,such connectors 5704 may be useful in providing a more secure connectionfrom the source of negative pressure to a negative pressure treatmentsystem. The use of these connectors 5704 is optional, and may not benecessary in all embodiments described herein. In use, a tube 5740connected to the connector 5704 may pull, or other external forces maysomehow disengage the connector 5704 away from the channel 5716 to whichit is attached. In such situations, application of negative pressure tothe wound may be reduced or stopped. Further means to secure theconnector 5704 to the remainder of the system may, as described above,include bonding or attaching other layers of the treatment system, ifpresent, to the connector 5704. For example, this may include bonding atleast one of the layers 1510, 1514, 1518 to the connector 5704. Theconnectors 5704 may be designed so as to create a secure connection witha fabric or material used in a channel; when 3D fabrics or 3D knittedmaterials are used, some embodiments of the connector 5704 areconfigured to engage with or attach to a portion of the material orfibers of the material to create a more secure connection. Preferably,embodiments of the connector 5704 are able to withstand a pulling forceof up to 20 kg before disconnection and/or failure of the connectoroccurs, preferably such that the connector disengages from the channelit is connected to. It will be understood that other embodiments may beconfigured to withstand a lower pulling force, and may be tailored torelease so to prevent injury to a patient (for example, constriction ofthe suction adapter and/or drainage tubes around a limb).

FIGS. 4A-B illustrate an embodiment of the connector 5704 a comprisingtwo or more projections 5752 extending distally lengthwise from thepreferably cylindrical main body of the connector 5704 a. The main bodyalso comprises a central channel 5755 extending lengthwise through themain body of the connector 5704 a. The projections 5752 may additionallycomprise one or more barbs 5754 attached thereto. Preferably, thesebarbs 5754 are angled proximally so as to act as anchors when pushed orinserted into the channel 5716. In some embodiments, the barbs 5754 mayform an angle of 60° with the projection 5752. When the channel 5716 isa 3D fabric or knitted material, the barbs 5754 are configured to engageto the fibers therein, creating a more secure connection. At theproximal end of the connector 5704 a, a lip 5756, which may be providedin a frustoconical form, may also be provided for connection to a tube5740. The tube 5740 may be connected to the connector 5704 a (as well asthe other connectors described herein) for example by press-fitting,although other connections means are possible. The tube 5740 may be thesame as tube 5507 in FIG. 2J, or it may be any other tube used toprovide fluid communication with a source of negative pressure.

In FIGS. 4C-D, a connector 5704 b has a proximal portion configured tofit around the exterior portion of a tube 5740, whereby the proximalportion is approximately cylindrical and has a cylindrical openingconfigured to receive the tube 5740, which can be secured by apress-fit. At about the center of the connector 5704 b, a distallyextending barb 5744 can be provided to attach to the channel 5716.Channels 5745 are preferably molded around the centrally-located barb5744 and through the body of the connector 5704 b so as to permit theflow of fluid through the connector 5704 b and into the tube 5740.

FIG. 4E illustrates another embodiment of a connector 5704 c, whereinthe connector 5704 c comprises a central, distally extending rod 5746configured to be pushed into an inner region of the channel 5716. Theconnector 5704 c is approximately cylindrical at its distal end, andtapers to form a smaller cylinder at its proximal end. It is at leastpartially hollowed out and has an inner channel configured to conveyfluid from the material 5716 toward the tube 5740. At its proximal end,the connector 5704 c comprises a lip 5765 similar to the lip 5742described below in FIG. 4H, wherein the lip 5765 is configured to aid inmaintaining a connection to a tube 5740 pushed onto the proximal end ofthe connector 5704 c. In some configurations, the lip may 5765 may bemade from rubber.

FIG. 4F illustrates an embodiment of a connector 5704 d comprising a pin5747 designed to secure the channel 5716 to the connector 5704 d. Here,the connector 5704 d may be pushed into the channel 5716. Alternatively,the channel 5716 may split partly lengthwise, so that an outer portionof the channel 5716 surrounds the connector 5704 d when insertedtherein. The pin 5747 is then inserted through the material of thechannel 5716 and through apertures (not illustrated) in the connector5704 d. In some embodiments, the pin 5747 may have flared ends or othersecurement methods to prevent the pin 5747 from being displaced.

FIG. 4G illustrates a variation of the embodiment illustrated in FIG.4F. Here, the connector 5704 e may comprise a distally extendingprojection 5748 that extends over a portion of the channel 5716 and isconfigured to receive the pin 5747. In both of these embodiments, theconnectors 5704 d, 5704 e may also be formed by creating a hole for thepin 5747 into a tube (and optionally by cutting away the tube asnecessary), for example the tube 5740 illustrated previously, such thata separate connector piece is not necessary. Thus, a modified tube 5740can replace the connector 5704 d.

In FIG. 4H, the connector 5704 f comprises distally extending hookedbarbs 5741 that attach to upper and lower portions near the end of thechannel 5716. The barbs 5741 are preferably made of an elastic orspring-like material that provides a force sufficient to sink andmaintain the barbs 5741 into the material of the channel 5716. The bodyof the connector 5704 f is preferably hollow so as to act as a fluidconduit. Of course, it may also be internally divided into multiplefluid channels extending through the body of the connector 5704 f. Atthe other end of the connector 5704 f, a lip 5742 may be provided to aidthe connector 5704 in remaining connected to a tube 5740 so that fluidsmay be drained from the negative pressure treatment system.

FIG. 4I illustrates an embodiment of a cylindrical hollow connector 5704g similar to the embodiment illustrated in FIGS. 4A-B, this timeprovided with a distal, frustoconical tip 5744 molded around a centralchannel 5749 of the connector 5704 g. As with other embodiments, aproximal frustoconical lip 5750 may be provided so as to provide a moresecure connection to a tube 5740.

FIGS. 4J-L illustrates embodiments of a connector 5704 h comprising aflexible line 5760 extending distally from a enlarged distal end or lip5763 of the connector 5704 h and forming a loop back to the enlargeddistal end 5763. The line 5760 is configured to be received in acorresponding cavity 5762 formed on the enlarged distal end 5763 of theconnector 5704 h. In some embodiments, the line 5760 may have a taperedor barbed tip 5761 that is configured to securely lock into the cavity5762. The line 5760 may also be provided with one or more barbs 5764.The body of the connector 5704 h is preferably tubular so as to permitthe flow of liquid from the wound. In use, the line 5760 may be pushedinto the channel 5716 and looped around some or all of the material,followed by pushing the tip 5761 into the cavity 5762. The barbs 5764may be useful in securing the connector 5704 h to the channel 5716. Whenthe channel 5716 is constructed from a 3D knitted or 3D fabric material,the line 5760 may be used to loop around and through the fibers that mayextend through the middle part of the channel 5716, with the barbs 5764helping to engage these fibers. Once secured to the channel 5716, theconnector 5704 h may be connected to a tube or other connector 5740.

FIGS. 5A-I all illustrate an embodiment of a connector 5800 similar tothe connector 5704 a illustrated in FIGS. 4A-B. In the embodimentillustrated, the connector 5800 comprises a main cylindrical body 5804,a proximal lip 5856 and distal projections 5852. A central channel 5855extends lengthwise through the proximal lip 5856 and through the maincylindrical body. As illustrated in FIG. 5H, the central channel mayhave a substantially constant inner lumen at least through the proximallip 5856 and the main cylindrical body 5804.

The distal projections 5852 may include two or more projections 5852extending distally lengthwise from the preferably cylindrical main body5804 of the connector 5800. These projections 5852 may additionallycomprise one or more barbs 5854 attached thereto. For example, two barbs5854 are shown on each of the projections in FIGS. 5A-I. The barbs 5854may have sharp tips, or the tips may have rounded or blunt ends asillustrated in FIG. 5H. Preferably, these barbs 5854 are angledproximally (for example at an angle of 60° relative to the projections5852) so as to act as anchors when pushed or inserted into the channel5816 of a suction adapter (shown in FIG. 5I). The channel 5816 may bethe same as channel 5716 of FIG. 4I or the same as channels 5512 and5516 in FIGS. 2-3. When the channel 5816 is a 3D fabric or knittedmaterial, the barbs 5854 are configured to engage to the fibers therein,creating a more secure connection.

The proximal portion of the projections 5852 may also comprise areinforcing portion 5858 connecting the projections 5852 to the mainbody 5804, and which may be configured to provide additional strength.As illustrated in FIGS. 5B, 5C, 5G and 5H, the reinforcing portion 5858may provide the projections 5852 with increased thickness at a proximalend of the projections 5852. This reinforcing portion 5858 may alsoprovide additional resistance to minimize the likelihood of theprojections 5852 becoming bent or twisted, for example when beinginserted into the channel 5816. As illustrated in FIG. 5H, in oneembodiment the distance between opposite projections 5852 may be largerthan the diameter of the central channel 5855. The reinforcing portion5858 in this embodiment serves as a transition along the inner surfaceof the projections 5852 to taper the opposing distance of theprojections 5852 to the diameter of the central channel 5855.

In some embodiments, the distal end of the cylindrical body 5804 alongits outer surface may be provided with an enlarged shoulder 5859, whichis preferably rounded when viewed in profile in FIGS. 5B-E. Viewed fromthe bottom (as shown in FIG. 5G), part of the shoulder 5859 may beflattened to reduce its width along certain axes. If so provided, thisshoulder 5859 may aid in securing the connector 5800 together with thebarbs 5854 to the channel 5816. The outer diameter of the shoulder 5859is preferably smaller than the distance between opposing barbs 5854.

At the proximal end of the connector 5800, a lip 5856, which may beprovided in a frustoconical form, may also be used for connection to atube 5840. In some embodiments, the lip 5856 may have a rounded proximaledge that may facilitate connecting to the tube 5840. As illustrated, inone embodiment the lip 5856 increases in outer dimension from itsproximal end toward its distal end. At the distal end of the lip 5856,there is a step-down in outer dimension to the main cylindrical body5804. The tube 5840 may be connected to the connector 5800 (as well asthe other connectors described herein) for example by press-fitting,although other connections means are possible.

With reference to FIG. 5H, the central channel 5855 is preferably of aconstant internal diameter between the proximal end of the connector5804 and the distal end of the shoulder 5859 before the projections5852. In some embodiments, the internal diameter of the central channelmay range between 0.07-0.25 inches, for example 0.12 inches. Thedistance between the inner surfaces of opposing projections 5852 maytypically be larger, preferably between 0.1-0.2 inches, for example0.126 inches. The outer diameter of the main cylindrical portion 5804 ofthe connector 5800 preferably ranges between 0.1-0.55 inches, forexample 0.19 inches. The lip 5856, as described previously, ispreferably larger in diameter, and may measure between 0.2-0.3 inches,for example 0.25 inches, at its distal end or base. In some embodiments,the length of the entire connector 5800 including the projections 5852may measure between 0.5-1 inch, for example 0.77 inches. The main bodyof the connector 5804, including the proximal lip 5856 and the shoulder5859, may measure in length between 0.25 and 0.75 inches, for example0.52 inches. The lip 5856 may measure in length between 0.1 and 0.3inches, for example 0.2 inches. The shoulder 5859 may measure in lengthbetween 0.05 and 0.15 inches, for example 0.08 inches. The projections5852 may measure in length between 0.15-0.3 inches, for example 0.25inches, while the barbs 5854 may measure in length between 0.05-0.08inches, for example 0.068 inches.

Although preferred dimensions have been provided for one embodiment of aconnector 5800, it will be appreciated that connectors for use innegative pressure with other dimensions are also contemplated. Thisincludes connectors having a length (including projections) of between0.5 to 3 inches (between or about 0.5 to about 3 inches) and an innerdiameter (of the central channel 5855) of between 0.05 to 1 inch.Suitable materials for the connector 5800 may include polymers, forexample but without limitation polymers such as polypropylene,polyethylene, polystyrene, and blends thereof.

With reference again to FIG. 5I, the pulling force necessary to dislodgethe connector 5800 (or any of the other connectors described herein)from the channel 5816 may be configured based on a number of factors.For example, the type and configuration of material used in the channel5816 may be particularly selected, using materials and configurationssuch as described above. In addition, several features in the connector5800 may be configured to determine how easily the connector 5800 isdislodged from the channel 5816. For example, the length and number ofprojections 5852, as well as the length and number of the barbs 5854 maybe particularly configured. Further, the force necessary to buckle,yield or snap off the barbs 5854 also affects the pulling forcenecessary to dislodge the connector 5800. Additional factors, such asmaterials selection, post-processing of materials, adhesives, or othercharacteristics of the connector 5800, the channel 5816, and/or otheraspects of the negative pressure treatment system may thus be tailoredto modify the pulling force necessary to disconnect the connector 5800from the channel 5816. In some embodiments, the pulling force sufficientto dislodge the connector 5800 from the channel 5816 may be tailored tofall within a range, for example, of between 1 kg to 100 kg, preferablybetween 10 kg to 50 kg, more preferably 20 kg or more as describedabove.

In some embodiments, the pulling force required to dislodge ordisconnect any of the connectors described above may be optimized toprovide a safety feature. For example, should an embodiment of thenegative pressure treatment system 5502 become entangled or trappedwhile applied to a patient, the pulling force can be tailored so that aconnector such as connector 5800 disconnects from the channel 5516 undersuch force. When the connector 5800 disconnects from the channel 5516, aseparation may form between the connector and the channel layer. Thelayers 5514 and 5518 from the embodiment illustrated in FIG. 2D may thencome together due to the negative pressure being applied to form apartial or complete seal. The resulting partial or complete blockage maybe detected by a sensor and an alarm activated to alert the user to aproblem with the system. In some embodiments, application of negativepressure may also be stopped upon detection of the blockage. In otherembodiments the disconnection of the connector 5800 may also be senseddirectly by a sensor placed adjacent the connector 5800, which may thenset off an alarm. Accordingly, patient safety may be enhanced byreducing the likelihood of the system 5502 entangling a portion of apatient (e.g., a patient limb, causing a tourniquet effect) orstrangling the patient.

The preceding embodiments illustrated in FIGS. 4A-L and 5A-I all shareelements that make them suitable for incorporation into a flexiblesuction adapter system of the type described previously, and inparticular for securement to a channel material such as a 3D fabric.Elements of the embodiments of connectors featuring barbs (such as FIGS.4A-D, H, J-L; 5A-I) could be combined with other embodiments ofconnectors featuring pins (such as FIGS. 4F-G) to form an even moresecure connection to a channel material. It will also be appreciatedthat the features of these connectors, particularly at the distal ends,can be incorporated onto the ends of tubes used to communicate negativepressure, such that those tubes can be directly connected to the suctionadapter system.

While the above detailed description has shown, described, and pointedout novel features as applied to various embodiments, it will beunderstood that various omissions, substitutions, and changes in theform and details of the device or process illustrated may be madewithout departing from the spirit of the disclosure. Additionally, thevarious features and processes described above may be used independentlyof one another, or may be combined in various ways. All possiblecombinations and subcombinations are intended to fall within the scopeof this disclosure. Many of the embodiments described above includesimilar components, and as such, these similar components can beinterchanged in different embodiments.

Although the invention has been disclosed in the context of certainembodiments and examples, it will be understood by those skilled in theart that the invention extends beyond the specifically disclosedembodiments to other alternative embodiments and/or uses and obviousmodifications and equivalents thereof. Accordingly, the invention is notintended to be limited by the specific disclosures of preferredembodiments herein.

What is claimed is:
 1. A negative pressure wound treatment systemcomprising: a wound dressing; an elongate bridge comprising: a fluidchannel comprising a fabric material; and an enlarged distal endconfigured to be attached to the wound dressing; and a connectorconfigured to connect to a conduit which is configured to delivernegative pressure to the wound from a source of negative pressure, theconnector comprising: a proximal end configured to be coupled to theconduit; and a distal end coupled to the fluid channel comprising thefabric material; wherein the distal end of the connector extends intoand beyond a proximal end of the fabric material and is adhered withinthe fabric material such that the fabric material surrounds a portion ofthe connector, and wherein the distal end of the connector comprises oneor more projections extending distally from the connector, eachprojection configured to adhere to the fabric material, and eachprojection including at least one at least partially laterally extendingbarb.
 2. The system of claim 1, wherein the connector further comprisesa lip at the proximal end of the connector, the lip configured to bepress fit with the conduit.
 3. The system of claim 2, wherein the liphas a frustoconical shape.
 4. The system of claim 1, wherein theconnector further comprises a hollow cylindrical body extending betweenthe proximal end and the distal end of the connector and a centralchannel extending through the hollow cylindrical body.
 5. The system ofclaim 1, wherein the wound dressing comprises a cover layer configuredto be positioned over a wound and sealed to skin surrounding the wound.6. The system of claim 1, wherein the elongate bridge is configured toattach to the wound dressing and surround at least one aperture formedin the wound dressing.
 7. The system of claim 1, wherein the fabricmaterial comprises knitted fibers.
 8. The system of claim 1, wherein thefabric material comprises nylon.
 9. The system of claim 1, wherein theconnector is configured to withstand a pulling force of up to 20 kgbefore disengaging from the fabric material.
 10. A negative pressurewound treatment system comprising: a wound dressing comprising a coverlayer configured to be positioned over a wound and sealed to skinsurrounding the wound; and a suction adapter comprising: a top layerconstructed from a liquid impermeable material; a bottom layerconstructed from a liquid impermeable material; a spacer layer locatedbetween the top and bottom layers, the spacer layer comprising a fabricmaterial; an elongate channel extending between the top and bottomlayers containing the spacer layer, wherein the top layer and the bottomlayer include enlarged distal ends with the channel extending in aproximal direction away from the enlarged ends; wherein the suctionadapter is configured to attach to the cover layer and surround at leastone aperture formed in the cover layer; and a connector configured toconnect to a conduit which is configured deliver negative pressure tothe wound from a source of negative pressure, the connector comprising:a proximal end configured to be coupled to the conduit; and a distal endcoupled to the elongate channel containing the spacer layer; and whereinthe distal end of the connector extends into and beyond a proximal endof the spacer layer and is adhered within the fabric material of thespacer layer such that the fabric material surrounds a portion of theconnector and wherein the distal end of the connector comprises one ormore projections extending distally from the connector, each projectionconfigured to be pushed into and be retained within the fabric materialof the elongate channel, and each projection including at least one atleast partially laterally extending barb.
 11. The system of claim 10,wherein the connector further comprises a frustoconical lip at theproximal end of the connector, the lip configured to be press fit withthe tube.
 12. The system of claim 10, wherein the connector furthercomprises a hollow cylindrical body extending between the proximal endand the distal end of the connector and a central channel extendingthrough the hollow cylindrical body.
 13. The system of claim 10, whereinthe fabric material comprises knitted fibers.
 14. The system of claim10, wherein the fabric material comprises nylon.
 15. The system of claim10, wherein the connector is configured to withstand a pulling force ofup to 20 kg before disengaging from the fabric material.
 16. The systemof claim 1, wherein a portion of the connector hooks onto fibers of thefabric material.
 17. The system of claim 10, wherein a portion of theconnector hooks onto fibers of the fabric material.